How often do you change your oil?

I really think this oil change every 3000 miles is not necessary, but at the same time in an older vehicle, it might be needed.

In general, I follow the manufacturer's guidelines for oil and filter replacement. My only "addition" to that is that if the manufacturer recommends oil change intervals of 5000 miles or more, I use synthetic or semi-synthetic oil. In my R51, I replace the oil at the factory specified 7500 interval under the "normal" service shedule. I get semi-synthetic 5W30 oil for free from my boss, so I use that, and a genuine Nissan or Purolator Pure-One filter (when I don't have a Nissan filter handy). Before mt boss started buying semi-synthetic in bulk, I was using Walmart's Syntech full synthetic, which is made by Royal Shell, the makers of Shell's Rotella oil. It's a good deal less expensive than the "name brand" synthetics, like Mobil 1 and Castrol. Oil has come a long way over the years and even conventional oil can withstand 7500 mile intervals under most circumstances. Everyone has their preferance of brand, but the most important thing is that the oil is API certified (American Petroleum Institure). Most are and there will be a stamp on the bottle indicating that, if it is.